Management of Patients With Refractory Angina: Canadian Cardiovascular Society/Canadian Pain Society Joint Guidelines

Impact of Cell Therapy on Myocardial Perfusion and Cardiovascular Outcomes in Patients With Angina Refractory to Medical Therapy: A Systematic Review and Meta-Analysis

RATIONALE

The effect of stem/progenitor cells on myocardial perfusion and clinical outcomes in patients with refractory angina remains unclear because studies published to date have been small phase I-II trials.

OBJECTIVE

We performed a meta-analysis of randomized controlled trials to evaluate the effect of cell-based therapy in patients with refractory angina who were ineligible for coronary revascularization.

METHODS AND RESULTS

Several data sources were searched from inception to September 2015, which yielded 6 studies. The outcomes pooled were indices of angina (anginal episodes, Canadian Cardiovascular Society angina class, exercise tolerance, and antianginal medications), myocardial perfusion, and clinical end points. We combined the reported clinical outcomes (myocardial infarction, cardiac-related hospitalization, and mortality) into a composite end point (major adverse cardiac events). Mean difference (MD), standardized mean differences, or odds ratio were calculated to assess relevant outcomes. Our analysis shows an improvement in anginal episodes (MD, -7.81; 95% confidence interval [CI], -15.22 to -0.41), use of antianginal medications (standardized MD, -0.59; 95% CI, -1.03 to -0.14), Canadian Cardiovascular Society class (MD, -0.58; 95% CI, -1.00 to -0.16), exercise tolerance (standardized MD, 0.331; 95% CI, 0.08 to 0.55), and myocardial perfusion (standardized MD, -0.49; 95% CI, -0.76 to -0.21) and a decreased risk of major adverse cardiac events (odds ratio, 0.49; 95% CI, 0.25 to 0.98) and arrhythmias (odds ratio, 0.25; 95% CI, 0.06 to 0.98) in cell-treated patients when compared with patients on maximal medical therapy.

CONCLUSIONS

The present meta-analysis indicates that cell-based therapies are not only safe but also lead to an improvement in indices of angina, relevant clinical outcomes, and myocardial perfusion in patients with refractory angina. These encouraging results suggest that larger, phase III randomized controlled trials are in order to conclusively determine the effect of stem/progenitor cells in refractory angina.

Management of Refractory Angina Pectoris

With improvements in survival from coronary artery disease (CAD) and an ageing population, refractory angina (RA) is becoming an increasingly common clinical problem facing clinicians in routine clinical practice. These patients experience chronic symptoms in the context of CAD, characterised by angina-type pain, which is uncontrolled despite optimal pharmacological, interventional and surgical therapy. Although mortality rates are no worse in this cohort, patients experience a significantly impaired quality of life with disproportionately high utilisation of healthcare services. It has been increasingly recognised that the needs of RA patients are multifactorial and best provided by specialist multi-disciplinary units. In this review, we consider the variety of therapies available to clinicians in the management of RA and discuss the promise of novel treatments.

The CREATE Method for Expressing Continuous Outcome Data in Absolute Terms for Use in Patient Treatment Decision Aids: A Validation Study

BACKGROUND

Patient decision aids (PtDAs) supplement advice from health care professionals by communicating the absolute risk or benefit of treatment options (i.e., X/100). As such, PtDAs have been amenable to binary outcomes only. We aimed to develop and test the validity of the Conversion to Risk Estimates through Application of Normal Theory (CREATE) method for estimating absolute risk based on continuous outcome data.

METHODS

CREATE is designed to derive an estimate of the proportion of those who experience a clinically relevant degree of change (CRDoC). We used a 2-stage validation process using real and simulated change score data, respectively. First, using raw data from published intervention trials, we calculated the proportion of patients with a CRDoC and compared that with our CREATE-derived estimate using chi-square tests of association. Second, 200,000 simulated distributions of change scores were generated with widely varying distribution characteristics. Actual and CREATE-derived estimates were compared for each simulated distribution, and relative differences were summarized graphically.

RESULTS

The absolute difference between the estimated and actual CRDoC did not exceed 5% for any of the samples based on real data. Applying the CREATE method to 200,000 simulated scenarios demonstrated that the CREATE method should be avoided for outcomes where the underlying distribution can be reasonably assumed to have high levels of skew or kurtosis.

CONCLUSION

Our results suggest that standard statistical theory can be used to estimate continuous outcomes in absolute terms with reasonable accuracy for use in PtDAs; caution is advised if outcome summary statistics are assumed to have been derived from highly skewed distributions.

Enhanced External Counterpulsation Is Cost-Effective in Reducing Hospital Costs in Refractory Angina Patients

BACKGROUND

Enhanced external counterpulsation (EECP) is effective in the treatment of refractory angina, a condition suffered by 1.7 million Americans. Declining cardiovascular mortality and appropriate use criteria may further increase this number.

HYPOTHESIS

EECP is hypothesized to be cost-effective in reducing hospitalizations in refractory angina patients.

METHODS

The data used in this analysis were collected in phase II of the International EECP Patient Registry (IEPR-II). Data were collected on changes in Canadian Cardiovascular Society functional class, Duke Activity Status Index, and number of hospitalizations in the 6 months prior to EECP and in the 6- and 12-month intervals following EECP. Estimates of the changes in annual cost of all-cause hospitalization before and after EECP therapy were calculated by the product of the differences in hospitalization rates in the 6-month interval before and after EECP treatment and estimated hospitalization and physician charges after subtracting the average cost of EECP.

RESULTS

Data for 1015 patients were analyzed. Hospitalization occurred in 55.2% of patients, an average of 1.7 ± 1.4 hospitalizations/patient, in the 6-month period before 35 hours of EECP; and in 24.4%, an average of 1.4 ± 1.0 hospitalizations/patient, during the 6- to 12-month period after EECP. The average hospitalization and physician charge in the US was $17,995, and the average EECP cost was $4880, yielding an annual cost savings/patient of $17,074.

CONCLUSIONS

Treatment of refractory angina patients with EECP resulted in improvement in angina and functional class accompanied by a sustained reduction in health care costs over 1 year of follow-up.

Transmyocardial laser revascularization versus medical therapy for refractory angina

BACKGROUND

This is an update of a review previously published in 2009. Chronic angina and advanced forms of coronary disease are increasingly more frequent. In spite of the improvement in the efficacy of available revascularization treatments, a subgroup of patients continue suffering from refractory angina. Transmyocardial laser revascularization (TMLR) has been proposed to improve the clinical situation of these patients.

OBJECTIVES

To assess the effects (both benefits and harms) of TMLR versus optimal medical treatment in people with refractory angina who are not candidates for percutaneous coronary angioplasty or coronary artery bypass graft, in alleviating angina severity, reducing mortality and improving ejection fraction.

SEARCH METHODS

We searched the following resources up to June 2014: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the metaRegister of Controlled Trials database, ClinicalTrials.gov, and the WHO International Clinical Trials Registry. We applied no languages restrictions. We also checked reference lists of relevant papers.

SELECTION CRITERIA

We selected studies if they fulfilled the following criteria: randomized controlled trials (RCTs) of TMLR, by thoracotomy, in patients with Canadian Cardiovascular Society or New York Heart Association angina grade III-IV who were excluded from other revascularization procedures.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data for each trial about the population and interventions compared and assessed the risk of bias of the studies, evaluating randomisation sequence generation, allocation concealment, blinding (of participants, personnel and outcome assessors), incomplete outcome data, selective outcome reporting, and other potential sources of bias.

MAIN RESULTS

From a total of 502 references, we retrieved 47 papers for more detailed evaluation. We selected 20 papers, reporting data from seven studies, which included 1137 participants, of which 559 were randomized to TMLR. Participants and professionals were not blinded, which suggests high risk of performance bias. Overall, 43.8% of participants in the treatment group decreased two angina classes, as compared with 14.8% in the control group: odds ratio (OR) 4.63, 95% confidence interval (CI) 3.43 to 6.25), and heterogeneity was present. Mortality by intention-to-treat analysis was similar in both groups at 30 days (4.0% in the TMLR group and 3.5% in the control group), and one year (12.2% in the TMLR group and 11.9% in the control group). However, the 30-day mortality as-treated was 6.8% in the TMLR group and 0.8% in the control group (pooled OR was 3.76, 95% CI 1.63 to 8.66), mainly due to a higher mortality in participants crossing from standard treatment to TMLR. The assessment of subjective outcomes, such as improvement in angina, was affected by a high risk of bias and this may explain the differences found. Other adverse events such as myocardial infarction, arrhythmias or heart failure, were not considered in this review, as they were not predefined outcomes in trials design and they show a high inconsistency across studies. No new trials on transmyocardial laser revascularization have been published in the last ten years and it is very unlikely that new research will be undertaken in this field.

AUTHORS' CONCLUSIONS

This review shows that risks associated with TMLR outweigh the potential clinical benefits. Subjective outcomes are subject to high risk of bias and no differences were found in survival, but a significant increase in postoperative mortality and other safety outcomes suggests that the procedure may pose unacceptable risks.

Efficacy of a device to narrow the coronary sinus in refractory angina

BACKGROUND

Many patients with coronary artery disease who are not candidates for revascularization have refractory angina despite standard medical therapy. The balloon-expandable, stainless steel, hourglass-shaped, coronary-sinus reducing device creates a focal narrowing and increases pressure in the coronary sinus, thus redistributing blood into ischemic myocardium.

METHODS

We randomly assigned 104 patients with Canadian Cardiovascular Society (CCS) class III or IV angina (on a scale from I to IV, with higher classes indicating greater limitations on physical activity owing to angina) and myocardial ischemia, who were not candidates for revascularization, to implantation of the device (treatment group) or to a sham procedure (control group). The primary end point was the proportion of patients with an improvement of at least two CCS angina classes at 6 months.

RESULTS

A total of 35% of the patients in the treatment group (18 of 52 patients), as compared with 15% of those in the control group (8 of 52), had an improvement of at least two CCS angina classes at 6 months (P=0.02). The device was also associated with improvement of at least one CCS angina class in 71% of the patients in the treatment group (37 of 52 patients), as compared with 42% of those in the control group (22 of 52) (P=0.003). Quality of life as assessed with the use of the Seattle Angina Questionnaire was significantly improved in the treatment group, as compared with the control group (improvement on a 100-point scale, 17.6 vs. 7.6 points; P=0.03). There were no significant between-group differences in improvement in exercise time or in the mean change in the wall-motion index as assessed by means of dobutamine echocardiography. At 6 months, 1 patient in the treatment group had had a myocardial infarction; in the control group, 1 patient had died and 3 had had a myocardial infarction.

CONCLUSIONS

In this small clinical trial, implantation of the coronary-sinus reducing device was associated with significant improvement in symptoms and quality of life in patients with refractory angina who were not candidates for revascularization. (Funded by Neovasc; COSIRA ClinicalTrials.gov number, NCT01205893.).

OSA and depression are common and independently associated with refractory angina in patients with coronary artery disease

OBJECTIVE

Refractory angina is a severe form of coronary artery disease (CAD) characterized by persistent angina despite optimal medical therapy. OSA and depression are common in patients with stable CAD and may contribute to a poor prognosis. We hypothesized that OSA and depression are more common and more severe in patients with refractory angina than in patients with stable CAD.

METHODS

We used standardized questionnaires and full polysomnography to compare consecutive patients with well-established refractory angina vs consecutive patients with stable CAD evaluated for coronary artery bypass graft surgery.

RESULTS

Patients with refractory angina (n = 70) compared with patients with stable CAD (n = 70) were similar in sex distribution (male, 61.5% vs 75.5%; P = .07) and BMI (29.5 ± 4 kg/m2 vs 28.5 ± 4 kg/m2, P = .06), and were older (61 ± 10 y vs 57 ± 7 y, P = .013), respectively. Patients with refractory angina had significantly more symptoms of daytime sleepiness (Epworth Sleepiness Scale score, 12 ± 6 vs 8 ± 5; P < .001), had higher depression symptom scores (Beck Depression Inventory score, 19 ± 8 vs 10 ± 8; P < .001) despite greater use of antidepressants, had a higher apnea-hypopnea index (AHI) (AHI, 37 ± 30 events/h vs 23 ± 20 events/h; P = .001), higher proportion of oxygen saturation < 90% during sleep (8% ± 13 vs 4% ± 9, P = .04), and a higher proportion of severe OSA (AHI ≥ 30 events/h, 48% vs 27%; P = .009) than patients with stable CAD. OSA (P = .017), depression (P < .001), higher Epworth Sleepiness Scale score (P = .007), and lower sleep efficiency (P = .016) were independently associated with refractory angina in multivariate analysis.

CONCLUSIONS

OSA and depression are independently associated with refractory angina and may contribute to poor cardiovascular outcome.

Interventional treatment of pain in refractory angina. A review

BACKGROUND

Refractory angina is characterized by repeated attacks of chest pain in patients on maximal anti-anginal pharmacotherapy, with a professional conscensus that further surgical or radiological revascularization would be futile. Refractory angina is a serious but relatively uncommon health problem, with a reported incidence of approximately 30 patients per million people/year. In this condition simply treating the associated pain alone is important as this can improve exercise tolerance and quality of life.

METHODS

An extensive literature search using five different medical databases was performed and from this, eighty-three papers were considered appropriate to include within this review.

RESULTS AND CONCLUSION

Available literature highlights several methods of interventional pain treatment, including spinal cord stimulation and video-assisted upper thoracic sympathectomy which can provide good analgesia whilst improving physical activities and quality of life. The positive effect of spinal cord stimulation on the intensity of pain and quality of life has been confirmed in nine randomized controlled trials. Other potential treatment methods include stellate ganglion blocks, insertion of thoracic epidural or spinal catheters and transcutaneous electrical nerve stimulation. These approaches however appear more useful for diagnostic purposes and perhaps as short-term treatment measures.

Development of a patient decision aid for people with refractory angina: protocol for a three-phase pilot study

Background

Refractory angina is a severe chronic disease, defined as angina which cannot be controlled by usual treatments for heart disease. This disease is frightening, debilitating, and difficult to manage. Many people suffering refractory have inadequate pain relief, continually revisit emergency departments for help, undergo repeated cardiac investigations, and struggle with obtaining appropriate care. There is no clear framework to help people understand the risks and benefits of available treatment options in Canada. Some treatments for refractory angina are invasive, while others are not covered by provincial health insurance plans. Effective care for refractory angina sufferers in Canada is critically underdeveloped; it is important that healthcare professionals and refractory angina sufferers alike understand the treatment options and their implications. This proposal builds on the recent Canadian practice guidelines for the management of refractory angina. We propose to develop a decision support tool in order to help people suffering from refractory angina make well-informed decisions about their healthcare and reduce their uncertainty about treatment options.

Methods

This project will be conducted in three phases: a) development of the support tool with input from clinical experts, the Canadian refractory angina guidelines, and people living with refractory angina, b) pilot testing of the usability of the tool, and c) formal preliminary evaluation of the effectiveness of the support tool to help people make informed decisions about treatment options.

Discussion

A decision support tool for refractory angina is needed and the available data suggest that by developing such a tool, we may be able to help refractory angina sufferers better understand their condition and the effectiveness of available treatment options (in their respective clinical settings) as well as their implications (e.g. risks vs. benefits). By virtue of this tool, we may also be able to facilitate identification and inclusion of patients’ values and preferences in the decision making process. This is particularly important as refractory angina is an intractable condition, necessitating that the selected course of treatment be lifelong. This study will yield a much needed patient decision aid for people living with refractory angina and pilot data to support a subsequent effectiveness study.

[Chronic chest pain]

BACKGROUND

Chest pain is a symptom commonly reported by persons in the general population and represents a differential diagnostic challenge.

MATERIAL AND METHODS

The paper is based on a narrative review with a selective search of the literature in Medline for reviews and guidelines on the prevalence and treatment of non-malignant diseases with chronic chest pain in gastroenterology, gynecology and cardiology.

RESULTS

The prevalence and current treatment recommendations for the different forms of gastroesophageal reflux disease (GERD), erosive and non-erosive types and irritable esophagus, non-cardiac chest pain, refractory angina in coronary heart disease and postmastectomy nand poststernotomy syndromes are presented. In cases of failure of the established therapy of a single medical discipline, an interdisciplinary assessment including psychosocial issues is recommended. Evidence-based guidelines are available for the management of GERD and of refractory angina. Treatment of postmastectomy and poststernotomy syndromes is based on case reports and expert opinion.

CONCLUSION

There is a need for controlled studies on the symptomatic treatment of pain in irritable esophagus, non-cardiac chest pain, postmastectomy and poststernotomy syndromes.

Impact of ranolazine on clinical outcomes and healthcare resource utilization in patients with refractory angina pectoris

BACKGROUND

Ranolazine is a novel antianginal medication approved for the treatment of chronic angina. There are only limited data concerning the efficacy of ranolazine in reducing healthcare resource utilization in patients with refractory angina pectoris.

OBJECTIVE

The primary objective of this analysis was to evaluate the efficacy and safety of ranolazine in refractory angina pectoris. In addition, the impact of ranolazine on healthcare resource utilization was assessed.

METHODS

Consecutive patients with refractory angina pectoris treated with ranolazine at two cardiology practices in the state of Nebraska were included in this analysis. The Canadian Cardiovascular Society (CCS) angina class and frequency and type of healthcare resource consumption were determined during the 12 months prior to and the 12 months after initiation of ranolazine.

RESULTS

A total of 150 pts (64 % men) with a mean age of 66 ± 12 years were included in this analysis. All patients had previously undergone coronary revascularization. Nitrates, β-adrenoceptor antagonists (β-blockers), and calcium antagonists (calcium channel blockers) were being used in 83, 97, and 75 % of patients, respectively. During ranolazine treatment, a significant improvement in CCS angina class was observed, with 23 patients improving by one class and no patient experiencing a deterioration in functional class (p = 0.025). A total of 53 side effects occurred in 28 (19 %) patients receiving ranolazine. Of those patients with side effects, four required dose reduction and seven required drug discontinuation. The frequency of clinic visits and emergency room visits was lower during ranolazine treatment, but the differences in frequency were not significant. The number of patients hospitalized and the number of hospitalizations were significantly lower during ranolazine therapy than in the pre-ranolazine study period (p = 0.002).

CONCLUSION

Ranolazine improved the CCS angina class and reduced hospitalizations over a 12-month follow-up period in a group of patients with difficult-to-treat refractory angina pectoris.

A phase II, sham-controlled, double-blinded study testing the safety and efficacy of the coronary sinus reducer in patients with refractory angina: study protocol for a randomized controlled trial

Background

A growing population of patients lives with severe coronary artery disease not amenable to coronary revascularization and with refractory angina despite optimal medical therapy. Percutaneous reduction of the coronary sinus is an emerging treatment for myocardial ischemia that increases coronary sinus pressure to promote a transcollateral redistribution of coronary artery in-flow from nonischemic to ischemic subendocardial territories. A first-in-man study has demonstrated that the percutaneous reduction of the coronary sinus can be performed safely in such patients. The COSIRA trial seeks to assess whether a percutaneous reduction of the coronary sinus can improve the symptoms of refractory angina in patients with limited revascularization options.

Methods/Design

The COSIRA trial is a phase II double-blind, sham-controlled, randomized parallel trial comparing the percutaneously implanted coronary sinus Reducer (Neovasc Inc, Richmond, BC, Canada) to a sham implantation in 124 patients enrolled in Canada, Belgium, England, Scotland, Sweden and Denmark. All patients need to have stable Canadian Cardiovascular Society (CCS) class III or IV angina despite optimal medical therapy, with evidence of reversible ischemia related to disease in the left coronary artery, and a left ventricular ejection fraction >25%. Participants experiencing an improvement in their angina ≥2 CCS classes six months after the randomization will meet the primary efficacy endpoint. The secondary objective of this trial is to test whether coronary sinus Reducer implantation will improve left ventricular ischemia, as measured by the improvement in dobutamine echocardiogram wall motion score index and in time to 1 mm ST-segment depression from baseline to six-month post-implantation.

Discussion

Based on previous observations, the COSIRA is expected to provide a significant positive result or an informative null result upon which rational development decisions can be based. Patient safety is a central concern and extensive monitoring should allow an appropriate investigation of the safety related to the coronary sinus Reducer.

Trial registration

ClinicalTrials.gov identifier - NCT01205893.

Women, cardiac syndrome X, and microvascular heart disease

New data suggest that persistent chest pain, despite normal coronary angiography, is less benign than previously thought. It has long been recognized that cardiac syndrome X (CSX) is associated with significant suffering, disability, and health care costs, but the biggest shift in thinking comes in terms of long-term risk. It is now recognized that the prognosis is not benign and that a significant proportion of patients are at increased cardiovascular disease risk. Of major debate is the question of whether the mechanisms that explain this chest pain are cardiac vs noncardiac. The most current definition of CSX is the triad of angina, ischemia, and normal coronary arteries, which is associated with an increased cardiovascular risk. This paper provides a review of CSX, epidemiology of the problem, proposed explanatory mechanisms, and important next steps in research. Central to this review is the proposition that new insights into CSX will be fostered by both clinical and scientific collaboration between cardiovascular and pain scientists.

Stable angina pectoris: the medical management of symptomatic myocardial ischemia

Coronary artery disease (CAD) remains an important cause of morbidity and mortality and is a serious public health problem. Over the last 4 decades there have been dramatic advances in the both the prevention and treatment of CAD. The management of CAD was revolutionized by the development of effective surgical and percutaneous revascularization techniques. In this review we discuss the importance of the medical management of symptomatic, stable angina. Medical management approaches to both the treatment and prevention of symptomatic myocardial ischemia are summarized. In Canada, organic nitrates, β-adrenergic blocking agents, and calcium channel antagonists have been available for the therapy of angina for more than 25 years. All 3 classes are of proven benefit in the improvement of symptoms and exercise capacity in patients with stable angina. Although there is no clear first choice within these classes of anti-anginal agents, the presence of prior or concurrent conditions (for example, prior myocardial infarction and/or hypertension) plays an important role in the choice of anti-anginal class in individual patients. For some patients, combinations of different anti-anginal agents can be effective; however it is recommended that this approach be individualized. Although not currently available in Canada, other classes of anti-anginal agents have been developed; their mechanism of action and clinical efficacy is discussed. Patients with stable angina have an excellent prognosis. Patients in this category who obtain relief from symptomatic myocardial ischemia may do well without invasive intervention.